共查询到19条相似文献,搜索用时 78 毫秒
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日本神钢电机公司开发了能够综合验证电力变换装置特性、性能等的仿真系统,它用计算机模拟太阳能发电及风力发电的实验数据.为提高太阳能及风力等自然能源的发电实用性,电力变换装置的性能至关重要,而这次开发的系统就是以提高该装置的性能为目的而开发的.做为综合了太阳能与风力的自然能源电力变换装置用的开发系统在日本尚属首创. 相似文献
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ND-Polya类比实现技术 总被引:2,自引:0,他引:2
从认识论和方法论的角度来看,分类不是认识事物解决问题的唯一方法,类比同样十分重要.然而传统的继承只体现分类的方法.自行设计的面向对象语言ND-Polya通过引入新的继承机制——柔性继承来支持类比方法.使用柔性继承机制,程序员能以描述事物或问题间相似性的方式进行软件开发.文中简要介绍了ND-Polya的柔性继承设施,并在此基础上具体地讨论了该机制的类比实现技术. 相似文献
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分布式计算机系统及应用的研究与开发,是当前世界计算机科学界的一个主要研究方向。该文探讨了分布式并行科学计算中的一些问题,介绍了用分布式算法求解快速傅立叶变换的实现方法及其计算结果。 相似文献
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离散小波变换算法剖析及其通用程序实现 总被引:1,自引:0,他引:1
针对小波变换工程应用软件开发需要,结合Mallat算法原理分析介绍了离散小波变换的主要功能步骤以及程序设计技术的关键问题.算法采用Delphi语言实现,大量数据验算表明,程序运算中间及最终结果和用Matlab小波工具箱编写的小波变换程序执行情况完全一致.主要算法均以子函数形式给出,便于研究人员把在Matlab中开发的小波变换应用算法成果转化为其它高级语言程序,构建独立的专用软件系统. 相似文献
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为满足对流层无线通信系统设计和优化的需要,基于抛物型波动方程和分步小波变换,研究了对流层电波传播特性,开发了电波传播特性分析软件。首先,通过建立数值求解的计算场景,给出了一种基于分步小波变换的对流层电波传播特性分析方法;其次,基于提出的分析方法和Matlab,开发了对流层电波传播特性分析软件。数值计算表明,提出的分步小波变换方法收敛性比分步傅里叶变换方法好;对流层传播损耗与天线高度和仰角密切相关,天线仰角越小传播损耗也越小,天线高度越大传播损耗越小;蒸发波导环境下的传播损耗比标准大气环境下的传播损耗要小。此外,开发的分析软件图形用户界面友好,操作简单、灵活。 相似文献
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小波变换的计算机实现 总被引:2,自引:0,他引:2
小波变换是傅里叶变换的改进,在工程领域中得到了广泛应用。本文主要结合MATLAB介绍小波变换的计算机实现,包括三种类型的小波变换。文中首先介绍了连续小波变换的数值积分实现,接着介绍了多分辨率分析和Mallat算法,最后用滤波器组实现了离散网格上的小波变换和离散序列的小波变换。 相似文献
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引入了计算机图形学中基本变换的基本理论,探讨了ToolBook中图形对象的移动和放大的方法,并通过一些具体的实例阐述了图形变换技术在开发CAI课件中的应用。 相似文献
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基于线性表出的非奇异循环变换局部性优化方法 总被引:1,自引:0,他引:1
开发程序的局部性是当今并行编译优化研究的重点之一,而程序变换是开发程序时间局部性和空间局部性的重要手段之一.该文提出了一种新的利用非奇异循环变换来优化程序局部性的局部性优化方法,即基于线性表出的循环变换.该方法利用一组最少的线性无关向量组来线性表出数组访问的下标表达式,并据此构造非奇异变换矩阵来优化数组访问的时间局部性和空间局部性.该方法能充分开发数组访问的时间局部性,能简便地确定是否能对数组访问进行时间局部性或空间局部性优化,并能对给定的嵌套循环同时进行时间局部性和空间局部性优化.实验结果表明了该文所提出的基于线性表出的非奇异循环变换局部性优化方法是有效的. 相似文献
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ND—Polya类比实现技术 总被引:1,自引:1,他引:0
从认识论和方法论的角度来看,分类不是认识事物解决问题的唯一方法,类比同样十分重要然而传统的继承只体现分类的方法,自行设计的面向对象语言ND-Polya通过引和新的继承机制-柔性继承来支持类比方法。 相似文献
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In this paper, we study the buffer queueing behaviour in high-speed networks. Some limited analytical derivations of queue models have been proposed in literature but their solutions are often a great mathematical challenge. We propose to use the Polya distribution to overcome such limitations. The specific behaviour of an IP interface with bursty traffic and long-range dependence is investigated by a version of the “classical” M/D/n queueing model called Polya/D/n. This is queueing system with a Polya input stream (a negative binomial distributed number of arrivals in a fixed time interval), a constant service time, multiple servers, and infinite waiting rooms. The model is considered a renewal process because of its quasi-random input stream and constant service time. We develop balance equations for the state of the system and obtain results for the packet loss and delay. The finding that the Polya distribution is adequate to model bursty input streams in IP network interfaces has motivated the proposal to evaluate the Polya/D/n system. It is shown that the variance in the input stream significantly changes the characteristics of the waiting system. The suggested model is new and allows defining different bursty traffic and evaluating losses and delays relatively easily. 相似文献
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Decision Support Systems (DSS) software is investigated and a conceptual model presented in this paper. The purpose of this model is to facilitate a better understanding of the nature of DSS software. The model is composed of six problem transformational processes linking up seven problem phases. The six transformational processes are: problem transforming system, problem mapping system, problem solving system, procedural program generation system, programming language compiling system, and code generation system, by identifying the seven problem phases this hierarchical provides a conceptual foundation for developing DSS software. Spun-off from this model is a framework for implementing knowledge-based DSS with automatic modeling capabilities. The structure of future DSS software to run on fifth generation computers is also addressed. 相似文献
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Mixture of Polya trees nonparametric estimation of a bivariate density is presented for interval censored data. Real and simulated data are analyzed and compared with nonparametric maximum likelihood (NPMLE) and Bayesian G-spline estimates. An advantage of the mixture of Polya trees approach over the NPMLE is the relative ease with which continuous bivariate density and hazard plots are obtained. 相似文献
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Aravind K. Joshi 《Pattern recognition》1973,5(4):365-381
Some specific aspects of language structure are examined in detail in the context of pattern analysis. In particular, a transformational grammar is constructed for a class of patterns, following the linguistic formulation very closely, by taking a simple example and working it out in detail. Many of the characteristics of the transformational grammars of linguists show up even in this simple example. The need for looking for grammars of different styles and the problem of making meaningful assignment of probabilities to sentences in the context of transformational grammars have also been briefly discussed. 相似文献
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Seung-Chun Lee 《Computational statistics & data analysis》2006,51(2):1012-1021
Recently the interval estimation of binomial proportions is revisited in various literatures. This is mainly due to the erratic behavior of the coverage probability of the well-known Wald confidence interval. Various alternatives have been proposed. Among them, Agresti-Coull confidence interval has been recommended by Brown et al. [2001. Interval estimation for a binomial proportion. Statist. Sci. 16, 101-133] with other confidence intervals such as the Wilson interval and the equal tailed interval resulting from the natural noninformative Jefferys prior for a binomial proportion. However, it seems that Agresti-Coull interval is little bit wider than necessary when sample size is small, say n?40. In this note, an interval estimator is developed using weighted Polya posterior. It is shown that the confidence interval based on the weighted Polya posterior is essentially the Agresti-Coull interval with some improved features. 相似文献
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Bauer F.L. Moller B. Partsch H. Pepper P. 《IEEE transactions on pattern analysis and machine intelligence》1989,15(2):165-180
Formal program construction by transformations is a method of software development in which a program is derived from a formal problem specification by manageable, controlled transformation steps which guarantee that the final product meets the initial specification. This methodology has been investigated in the Munich project CIP (computer-aided intuition-guided programming). The research includes the design of a wide-spectrum language specifically tailored to the needs of transformational programming, the construction of a transformation system to support the methodology, and the study of transformation rules and other methodological issues. Particular emphasis has been laid on developing a sound theoretical basis for the overall approach 相似文献
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《IEEE transactions on pattern analysis and machine intelligence》1987,(8):967-976
A methodology, different from the existing ones, for constructing distributed programs is presented. It is based on the well-known idea of developing distributed programs via synchronous and centralized programs. The distinguishing features of the methodology are: 1) specification include process structure information and distributed programs are developed taking this information into account, 2) a new class of programs, called PPSA's, is used in the development process, and 3) a transformational approach is suggested to solve the problems inherent in the method of developing distributed programs through synchronous and centralized programs. The methodology is illustrated with an example. 相似文献
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Highly optimised algorithms are, in general, hard to understand. This is a consequence of the designer's sacrifice of clarity and modularity in favour of efficiency. In this paper we present a formal derivation of a rather ingenious algorithm, viz., the fast pattern matching algorithm of Boyer and Moore. The development illustrates that transformational programming combined with assertional reasoning provides an appropriate approach for developing and understanding highly optimised algorithms.This research has been carried out within the NFT-project STOP (Specification and Transformation Of Programs) and partially sponsored by NWO (Netherlands Organisation for Scientific Research) under grant NFI-FW3315. 相似文献